With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.4923-87-9,5-Bromobenzothiophene,as a common compound, the synthetic route is as follows.
To a pre-dried flask equipped with a condenser is added magnesium (568 mg, 23.4 mmol) and Et20 (5 mL). To this is ADDED-1/10 OF a solution of iodomethane (1.66 g, 11.7 mmol) and 5-bromo-benzo [b] thiophene (500 mg, 2.34 mmol) in Et20 (8 mL). After adding 2-3 crystals of iodine, the reaction mixture is heated to reflux using a hot water bath. After a few minutes the iodine coloration fades and another portion (-0. 5 mL) of the IODOMETHANE/5-BROMO-BENZO [b] thiophene solution is added. The water bath is removed and further additions (-0. 5 mL) are added such that reflux is sustained. After complete addition, reflux is maintained for 30 min using a hot water bath. The Grignard solution is then cooled TO 0 C and 3-pentanone (1.20 g, 14.0 mmol) is added dropwise. After 30 min, the ice is removed and the reaction mixture is stirred for 2 h. After cooling to 0 C9 the reaction is quenched with H20 (10 mL) and saturated aqueous NH4C1 (15 mL) and is diluted with Et2O (100 mL). The organic layer is washed with brine (35 ML) dried (MGS04), FILTERED and concentrated. The reaction residue is subjected to flash chromatography (silica gel, 90: 10 petroleum ETHER/ET2O) to afford impure sub-title compound (-500 mg). Most of the impurity is removed under high vacuum (-2 d) to yield slightly impure sub-title compound (323 MG, 62#x0025;). RF 0. 43 (4: 1 Hex/EtOAc). 1H NMR (300 MHZ, CDCL3) # 0.77 (T, J = 7.4 HZ, 6H), 1.70 (S, 1H), 1.80-1.98 (SYM M, 4H), 7.32 (d, J= 5.4 Hz, 1H), 7.34 (dd, J= 1. 6,8. 5 Hz, 1H), 7.42 (d, J= 5.4 Hz, 1H), 7.82 (d, J=8. 5HZ, LH), 7.87 (d, J=1. 6 HZ, 1H).
4923-87-9, As the paragraph descriping shows that 4923-87-9 is playing an increasingly important role.
Reference£º
Patent; ELI LILLY AND COMPANY; WO2004/67529; (2004); A1;,
Benzothiophene – Wikipedia
Benzothiophene | C8H6S – PubChem